1. Field of the Invention
The present invention relates to a process and apparatus for electronic ignition control for an internal combustion engine, in particular for a motor vehicle.
2. Description of the Prior Art
Control of the ignition of an internal combustion engine implies the possibility of producing ignition pulses which are displaced with respect to the top dead centre position by an amount which should be suitably determined, in order to cause the engine which is controlled in this way to operate correctly.
A system of this type was described and claimed in patent application No 75/30 902 filed on Oct. 9, 1975 and its certificate of addition No 76/11 524 filed on Apr. 20, 1976 for "Process and apparatus for electronic ignition control for an internal combustion engine". With the appearance of new types of internal combustion engines which are associated with more restricted controls in respect of pollution and anti-pinging, it is becoming more and more difficult to exploit to the maximum the levels of performance which were anticipated.
Indeed, if the system has a certain degree of redundancy in regard to the number of laws in respect of correction of ignition advance by means of the depression, it is unsatisfactory by virtue of the form of the law for correction of ignition advance by depression and by virtue of the fact that, without supplementary means, it is impossible to make ignition advance corrections which are limited to one pressure speed range and which are initiated by external sensors which detect the water temperature in the engine cylinder head or the air temperature in the intake manifold.
The present invention makes it possible to overcome these disadvantages.